Hoist



Sept. 17, 1929.

C. J. WEBER ET AL HOIST Filed June 29, 1926 2 Sheets-Sheet indenara:

Patented Sept. 17,- 1929 UNITED STATES PATENT OFFICE CLARENCE J. AND ROYA- SEE K, OF CHICAGO, ILLINOIS, ASBIGNOBS TO NA- 'IIONLL BBICK'COHPANY,OF CHICAGO, ILLINOIS, A. CORPORATION OI ILLINOIS HOIST Application am!June 29, 19211. Serial No. 119,312.

Our invention pertains in general .to trucks or trailers and moreparticularly to hoisting mechanism therefor. we contemplate theprovision of improved mechanism for tiltin a truck or trailer body forthe purpose of discharging the contents therefrom with facility.

In hydraulic hoists for liftin the'front end of a body of a truck ortrai or, it is old to permit the hoist cylinder to move about itspivotal mounting as far as the body of the truck will permit. That is tosay, as the plunger in the cylinder is elevated, the end of the body isalso raised about its pivot,

pulling towards it the upper end of the cylinder. This movement of thecylinder has been usually taken care of by providing a pivotal mountingfor the lower end thereof. The primary disadvantage of this constructionwas that it permitted the cylinder to freely sway to and fro.

This swaying action is undesirable for two reasons. In the first lace,it increases to a considerable extent t e wear of the parts,

particularly the bearings associated, with the pivotal mounting for thec linder. In the second place, it causes the lifting cables to flex muchmore than is necessary and thus decreases the longevity of these cables.Also it is to be understood that this swaying action is deleterious tothe 'efliciency of the hoist itself in raising the end of the truckbody.

Now we propose to provide a hoist of the character mentioned abovewherein the movement of the cylinder is restricted. In fact, Wecontemplate ,the provision of mechanism for actually resisting thislateral movement of the hoist cylinder.

We have disclosed herein a construction with which we have attainedhighly desirable results. It comprises, in general, essentially aresilient mounting for the hoist cylinder. More specifically, itconsists of a spring device for resisting movement of the hoist cylinderabout its pivot. The degree of movement of the cylinder about its p votdepends upon the amount of the load 1mpos'ed thereon. In fact themovement 1s Specifically proportional to the weight of the load in thetruck body.

In accordance with the general features of our invention there isprovided a hoist cylinder having a: pivotal mounting and resilient meansassociated with the mountmg comprising a plurality of leaf springsadapted to at all times urge the cylinder into a true vertical positionwith respect to the chassis of the truck.

Also, we have from experience found that the cup leather associated withthe hoist piston tends to wear out much faster than is usual, due to thefact that it is flexed considerably. We have remedied this condition bypositioning the cup leather in a substantially central position withrespect to the piston, and by providing the piston with piston rings oneach side of the cup leather. These piston rings serve to confine thecup leather ,and also to relieve the cup leather of considerable wear bypreventing it from being flexed to any considerable extent.

In accordance with other features ofour invention, we have providednovel detachable connections between'the hoist cylinder and the sourceof hydraulic power, which connections permit of the cylinder beingdisconnected with facility from the hydraulic power unit. 4

In accordance with still other features of our invention, we provide inthe connections between the hoist and the pump a three way valveconstruction for controlling the operation of the hoist. This valvepermits of an oscillatory movement being imparted to the hoist. plungerto cause the same to jar the trailer body and thus cause allof thecontents thereof to be quickly discharged. Then, too, thevalve may beactuated to disconnect the. pump from the hoist cylinder and to thuscause the plunger to be maintained in a 'ven stationary osition or tocause all 0 the fluid to be ischarged into the tank to lower the hoistplunger depending upon the position of the yalve control member.

Other objects and advantages of our 1nvention will more fully appearfrom the following detailed descriptlon taken in connectibn with theaccompanging drawings which illustrate one embo iment thereof and inwhich,

Fig. 1 is a side elevation of a truck and trailer having associatedtherewith .a hoisting device embodying the features of our invention;

Fig. 2 is an enlarged view of the hoist cylinder and its pivotalmounting;

' Fig. 3 is a sectional view taken ,on the 'line 33 of Fig. 2 looking inthe direction indicated by the arrows;

Fig. 4 is a sectional view of our novel hoist piston construction; and

' Fig. 5 is an enlarged sectional view of the three-way control valveassociated with the pumping mechanism and oil tank.

Referring now to the drawings in detail, in which like referencenumerals designate similar parts throughout the several views, 10denotes generally a tractor (Fig. 1) which may be of any conventionalconstruction. The tractor 10 is provided with the usual turn table 11 towhich one end of a trailer 12 is connected. The tractor 10 and thetrailer 12 comprise a truck, such as is well known in the automotiveart. The trailer 12 is equipped with the customary body 13 having oneend pivotally attached at 14 to the rear of the trailer 12. The frontend of the body 13 is adapted to be raisedjto a position such as thatillustrated by dotted lines in Fig. 1.

The body 13 is adapted tonormally rest upon the frame 15 of the trailer12. The rear end of the frame 15 is provided with a pair of wheels 16and a pair of springs I 17. The front end of the frame 15 is adapted torest upon the turn table 11 associated with the chassis 18 of thetractor 10. Normally, the front end of the -frame 15 will be connectedto the said turn table 11.

The frame 18 of the tractor 10 carries a pair of gas'tanks 19 and 20which supply thefuel to the power unit of the tractor 10. These gasolinetanks 19 and 20 are positioned immediately behind the drivers station21.

Mounted upon the front end of the trailer frame 15 is a hoisting devicedesignated generally by the reference character 25. This device isadapted'to'be utilized to raise the body 13 about its pivot to aposit-ion such as that illustrated by dotted lines in Fig. 1. The device25 includes a vertical cylinder 26 4 and a reciprocable plunger 27mounted within the cylinder 26. The plunger 27 is preferably tubular inconstruction and has associated with its lower end a piston 28.

The piston 28 (Fig. 4) comprises a pair of annular members 29 and 30separated by a cup leather 31. The annular member 29 is equipped with areduced portion 32 which telescopes the lower end of the tubular plunger27. The reduced portion 32 may be fastened to the plunger 27 in anydesirable, manner. The annular member 29 is also provided with anannular stud 33 which extends through an aperture 34 in the center ofthe cup leather 31 and through an aperture 35 int e center of theannular member 30. The annular member 30 is prefer'ablyfequipped with anannular recess 36 in which a nut 37 is threaded upon the exposed end ofthe stud 33. This nut 37 serves to draw the members 29 and 30 togetherandserves to fasten the members and cup leather rigidly together. Thean- 'nular member 30 is provided with a reduced portion 38 between theperiphery of which and the inner wall of the cylinder I 26 is locatedthe annular'rim 39 of the cup leather 31. In other words, the annularmember 30 in reality telescopes the cup leather 31 and thus tends toprevent undue flexing of the cup leather. The annular member 29 isprovided with a piston ring 40 and the annular member 30 is providedwith a piston ring 41.

The piston rings 40 and 41 engage the inner periphery of the cylinder 26and serve to relieve the cup leather 31 of some of the strains andstresses imposed thereon when the plunger 27 ,is actuated. Since the cupleather 31 is confined intermediate the telescoping annular member 30and the inner wall 'of the cylinder 26 it cannot flex as freely as inprior piston constructions. This arrangement increases the longevity ofthe cup leatherand insures a reliable service on the part of the piston28. Heretofore, the cup leather was caused to be flexed considerablyupon' the reversal of the direction of movement of the plunger in thecylinder. In our construction the cup leather 31.cannot thus flex uponthe reversal of the movement of the plunger due to its being confinedintermediate the two members 29 and 30.

The upperend of the plunger 27 has fastened thereto a cross armconstruction 45 which carries a pair of revolvable pulleys 46. Eachpulley 46 is pivotally attached to an arm 47 pivotally bolted to thecross arm construction 45.

Referring now to Fig. 3, the upper end of the cylinder 26 is preferablythreaded and provided with a cap 50 threaded thereon. The cap 50 has aplurality of notches 51 preferably four in number for enabling thesameto be turned with facility. The plunger 27 extends through anaperture 52 in the cap 51. The aperture 52 is preferably countersunk asindicated at 53, in order to accommodate a gland member 54 threaded intothe upper part ofthe can 50. The gland member 54 is provided with acentral aperture 55 through which the plunger 27 extends.

The lower part of the cylinder 26 is tightly fitted in a pivotallymounted member 56. This member 56 is provided with a pair ofdiametrically opposed extensions 57 and 58 journaled in bearing brackets59 and 60. Thus it will be seen that the lower end of tlie plungercylinder 26 is pivotally mounte cured to portions 62 and 63 of a baseplate 64 by means of bolts 65. The portions 62 and63 are elevated fromthe plane of the base plate 64. The base plate 64 is provided with apair of flanges 66 and 67 bolted to the channel irons 68 and 69 of theframe 15. The base plate 64 is also equipped with a pair of raisedportions 71 and 72, upon each of which portions is supported a springconstruction designated encrally by therefer ence character 70. Sinceboth of the spring constructions are identical, .it is believed thedescription of one will suffice for both.

Each spring construction comprises a plurality of leaf springs 74 whichvary in length. The springs 74 are held together by means of the usualclip 75. The longest, leaf spring 74 abuts the outer wall of thecylinder 26, as indicated at 76. The lower ends of the leaf springs 74abut the top of the raised portion associated therewith. The springs arebolted to a lateral extension 78 projecting upwardly from the base plate64. A

clamping plate 79 and a plurality of bolts, and nuts 80 are preferablemployed for lateral extension clamping the springs to the 70 Now itwill be obvious that the spring construction 70 will normally functionto maintain the hoist cylinder 26 in a vertical Iposition with respectto the base plate 64. owever, upon the raising of the body 13 by theplunger 27, the cylinder 26 will begin to tilt about its pivot towardsthe rear of the trailer 12. This movement will be resisted by the springconstruction 70 nearest to the body 13. The degree to which the cylinder26 will pivot about the axis of its pivotal mounting will depend uponthe load in the body 13. That is to say, the tilting will beproportional to the weight of the load in the truck body 13.

. Each pulley 46 has passing over its groove a cable 80, one end ofwhich is fastened to a channel beam 81 of the body 13 and the other endof which is fastened to an eyelet 82 secured to the base place 64. Thepair of aibles 80 are utilized upon the raising of the pulleys 46 by theplunger 27 to raise the associated end of the body 13.

Associated with the cylinder 26 intermediate its ends is a ring ofmetallic material 90. This ring may be secured to the outer wall of thecasing or cylinder 26 by any suitable means. This ring 90 constitutes asupport for the flexible-connections to be hereinafter described.Fastened to this The bearing brackets 59 and 60 are seis connected to anoutlet in the cylinder wall 26, designated by the reference character93. The pipe line 92 may be provided with a a union 94 intermediate itsends to facilitate the disconnecting of the pi the cylinder 26 wheneverit is esired. Also secured to the ring 90 is a tubular block 91' whichis identical in construction to the block 91. Connected to this block91' is a pipe line 95, the lower end of which comline from municateswith an inlet 96 for the cylinder 26. The ipe line 95 is also equippedwith a union 9 positioned intermedlate its ends. Since both t 1e blocks91 and 91' are identical in construction, it is believed a descri tionof one will suflice for both.- Each lock 91 is provided with a lateralprojection 98 having a tapered orifice portlon 99. The

projection 98 is tubular in construction and communicates with the pipeline associated with the block.

Associated with the projections 98 of the blocks 91 and 91' are a pairof flexible lines 100 and 101. The line 100 constitutes the inlet leadfor the hoisting device and the line 101 constitutes the outlet forhoisting device. Each 0f these lines has an end provided with a metallicring of material 102 to which is pivotally attached a yoke member 103for straddling the associated projection 98. The yoke member 103 has anadjustable screw 104 adapted to be moved into engagement with the top ofthe corresponding ro'ection 98. The taipered portion 99 0? t eprojection is a apted to be inserted into the end of the pipeline andthe pipe line is adapted to be tightly held in lace on the projection byIt should of course be understood that the inlet pipe line 100 isassociated with the blok 91' communicating with the inlet pipe 95 andthat the pipe line 101 is associated with the block 91 communicatingwith the outlet 93. The detachable connections, including the yokemembers 103 previously described, enable the pipe lines 100 and 101 tobe detached from .the hoist cylinder 26 with facility. This isparticularly advantageous when it is desired to disconnect the trailerfrom the tractor.

Referring now to Fig. 1, it will be observed that the inlet pipe line100 communicates with a three-way valve 105. The flexible pipeconnection 101 has its other endconnected to a pipe 106 discharging intoan oil tank 107. The upper end of the pipe 106 communicates with thethree-way valve 105. The three-way valve is also connected by a flexibleconnection 107 to a pumpin mechanism, designated generally by the re.erence numeral 108. The pumping mechanism is connected by a pipe line109 to the bottom of the oil tank 107. The oiltank 107 and the pumpingmechanism 108 are preferably disposed intermediate the two gas tanks 19and 20, previously described.

We have illustrated somewhat diagrammatically in Fig. 5 a three-Wayvalve construction 105 for controlling the operation of our hoist. Thevalve proper includes a T body 111, a valve member 112 and a han trated,the pump will be forcing fluid or oil to the hoisting cylinder 26. Afterthe plunger 27 has been moved to its uppermost position, the oilentering the cylinder 26 from the pump will cause the plunger 27 tooscillate. This oscillatory movement on the part of the plunger 27 jarsthe body 13 and enables all of the contents to be dis-' chargedtherefrom quickly. Now, by operating the handle 110 to cause the valvemember 112 to close the port 115, the pumping mechanism 108 will bedisconnected from the three-way valve 105. in the plunger 27 forcing theoil out of the cylinder 26 through the pipe line 101, port 113, into theport'lll and into the tank 107, In other words when the port 115 isclosed, the plunger 27 will be moved to its lowermost position.

On the other hand, when the port 113 is closed, the plunger 27' will notoscillate, but, on the contrary, will remain at a given raised position.The oil pumped through the line 107' by the pump 108 will be bypassed bythe valve 105 into the tank 107. Thus it will be seen that through thethreeway valve 105 liquid may be either pumped to the hoist, by-passedto the tank. or the oil in the cylinder 13 may be caused to bedischarged into the tank or in the hoist plunger 27. I

We desire it understood that although we have described in detail thepreferred embodiment of our invention, the invention is not to belimited thereby, but only in so far as defined by the scope and spiritof the appended claims.

We claim 1. The combination with a reciprocable plunger and a cylindertherefor having one end pivotally mounted of resilient means comprisingtwo oppositely disposed leaf springs at each side of the cylinder, theends This will result of said springs being fixedly mounted adjacent. tothe cylinder support with the free ends of said springs slidinglycontacting the cylinder surface for at all times urging the cylinderinto a predetermined position and for resistin movement of the cylinderabout its pivot.

2. The combination with a reciprocable plunger and a cylinder thereforhaving one end pivotally'mounted of resilient means for at all timesurging the cylinder into a pre determined position and for resistingmovement of the cylinder about its pivot, said means comprising aplurality of leaf springs independent of the pivot for the cylinderadapted to engage opposite sides of the said cylinder.

3. In a hoisting device including a pivoted hoist cylinder and areciprocable plunger therein, resilient means for urging the plungerinto a predetermined position, said means comprising a plurality of leafsprings independent of the hoist pivot and engaging opposite sides ofthe cylinder to resist movement of the same about its pivot.

4. In a hoisting device including a hoist cylinder, a re'iprocableplunger therein, and a pivotal mounting for the cylinder, resilientmeans associated with the mounting for resisting movement of thecylinder about its pivot, said means comprising a plurality of leafsprings independent of the pivotal mounting for the cylinder adapted toengage opposite sides of the said cylinder.

5. In a hoisting device including a hoist cylinder, a reciprocableplunger therein, and a pivotal mounting for the cylinder, resilientmeans associated with the mounting for resisting movement of thecylinder about its pivot, said means including a plurality of fixed leafsprings independent of the hoist pivot and having their free endsengaging opposite sides of the cylinder for maintaining the cylinder ina given position.

6. In combination in a hoisting device, a hoist cylinder, a reciprocableplunger therein, a pivotal mounting for one end of the said cylinder, asupport for the said mounting, a lateral projection associated with thesaid support, a plurality of leaf springs asso ciated with the saidprojection and extending alongside the said cylinder, said leaf springshaving their free ends associated with the said cylinder for resistingmovement of the cylinder about its pivotal mounting, and means foractuating the said plunger.

7. In combination, in a hoisting device, a hoist cylinder,a reciprocableplunger therein, a pivotal mounting for one end of the said cylinder, asupport for the said mounting, resilient means associated with the saidsupport and in engagement with the periphery of the said cylinder fornormally maintaining the cylinder in a substantially vertical hoistcylinder, a reeiprocable plunger therein, a pivotal mounting for one endof the said cylinder including a pair of bearings, a

support for the said bearings, a lateral exr tension connected to thesaid support, a plurality of leaf springs connected to the saidextension, said springs extending alongside the said cylinder andserving to resist movement of the cylinder about its pivot, and meansfor actuating the plunger in the said cylinder.

9. In combination, an upright hoist member a pivotal mounting for thelower end of said hoist member, and means for yieldingly holding thehoist member in upright position and resisting pivotal movement of saidmemher about its pivotal mounting, said means comprising a pair ofoppositely disposed leaf springs extending along and engaging oppositesides of the cylinder and mounted at their lower ends on opposite sidesof the pivotal mounting for the cylinder and independently thereof.

10. in combination, in a truck including a hoist body, a hoist cylinderpivotally mounted on the said truck, a reciprocable plunger in the saidcylinder andmeans for actuatlng the same, a connection between theplunger and the body for enabling the raising of one end of the body todischarge the contents thereof and a leaf spring construction comprisingtwo oppositely disposed springs fixedl y mounted on the track with thefree ends thereof slidably engaging the sides of the cylinder, said leafsprings being entirely independent of the pivoted mounting of thecylinder for normally maintaining the cylinder in a given position withrespect to the truck and for resisting any swaying movenieutot thecylinder about its pivot during the time the said plunger is effectivein holding the said end of the body in an elevated position.

In witness whereof, We hereunto subscribe our names this 7th day ofApril, 1926.

CLARENCE J. WEBER. BUY A. SEEK.

